Automatic magnetic release for ironing machines



Oct. 9,, 1928.v

H. E. NEWHOUSE AUTOMATIC MAGNETIC RELEASE FOR IRONING IACHINES 2 Sheets-Sheet Filed 001;. 29. 1924 v vv INVENTOR flamer f. New/muse ATi'ORNEY Oct. 9, 1928.

H. E. NEWHOUSE AUTOMATIC MAGNETIC RELEASE FOR IRONING IATCHINES Filed 0ct. 29, 1924 2 Sheets-Sheet 2 INVENTOR hbmer f. /\/LU/7OU6 WITNESSES:

ATTORNEY Patented Oct. 9, 1928.

UNITED STATES PATENT OFFICE.

( HOMER ELNEWHOUSE, OF EAST PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WEST- INGHOUSE ELECTRIC 8a MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVAN IA.

AUTOMATIC MAGNETIC RELEASE FOR IRONING MACHINES.

\ Application filed October 29, 1924. Serial No. 746,475.

This invention relates to safety latches and more particularly to safety latches for noning machines.

The object of my invention, generally stated, is the provision of a safety latch WhlCh shall be simple and efficient in operation and readily and economically manufactured A more specific object of the invention is to i! provide for the locking of the ironing mem- |o bers of an ironing machine in predetermined relative positions to effect the ironing operations and the automatic release of the ironing members when they cease to function.

Another object of the invention is to pro- |5 Vide for the manual release, at will, of ironing members locked in ironing relation to permit their separation.

A further object of the invention is to provide for the throwing of the latch into and out of action by movement of the ironing members into and out of ironing relation.

, Other objects ofthe invention will, in part,

be obvious and in part appear "hereinafter.

The invention accordingly is disclosed in the embodiment thereof shown in the accompanying drawings and comprises the features of construction, combination of elements and arrangement of parts that will be exemplified in the construction hereinafter set forth and the scope of the application of which will be indicated in the appended claims.

For fuller understanding of the nature and objects of the invention, reference should be 'had to the following detailed description,

taken in connection with the accompanying drawing in which,

Figure 1 is an end elevation of an ironing machine provided with a safety latch constructed in accordance with this invention,

Fig. 2 is a front elevation of the safety latch, showing it in its locking position, and

Fig. 3 is a side'elevation of the safety latch, parts being broken away to show its construction.

' Fig. 4 is a view, partly insection, of a modification of the safety latch.

Fig. 5 is a wiring diagram showing the modified safety latch connected in the motor circuit, together with portions of the ironing machine structure, I V

Referring now to the drawing, 10 designates generally an ironing machine provided with a roll 11 and a shoe 12. In this particular construction, the shoe is movable and disposed to be projected into ironing relation with the roll.

It will 'be noted that the shoe-operating.

. nism was selected merely in the interest of simplicity of illustration and description and it is to be understood that the latch, to be described hereinafter, may be applied to manual and power-operated mechanisms of all kinds.

' An electric motor 15 is ing the roll and it may be connected to the latter by a train of reduction gears of any suitable type well known in the art. It may also be pointed out that this motor may be utilized to operate the shoe mechanism.

In order to lock the shoe 12 in ironing relation to the roll 11, a safety latch assemblaqe. shown generally at 27. is provided. As will be noted, the assemblage includes a casing 26 provided with lugs 24 perforated for the reception of screws or bolts, such as may be used for the mounting of the safety latch on the ironing-machine frame.

Pivotally mounted on a bracket 25 carried by the casing 26. is an L-shaped latch memher having a vertical arm disposed for movement into engagement with the treadle 13 when the latter is depressed. In this embodiment of the invention, the lower end of the vertical arm of the-latch is provided with a provided for drivshoulder adapted to seat on the treadle.

However, it will be readily understood that any other treadle-engaging means may be provided on the latch and it might also be adapted, for instance. by stepping the lower end, to retain the treadle in different positions to maintain different pressures between the ironing members.

An electromagnet 18 is mounted in'the casing 26 and disposed in alinement with an armature 23 provided on the end of the horizontal arm of the latch member. Therefore, when the electromagnet is energized, it tends to draw the armature downward and to oscillate the latch member. Accordingly if the treadle is depressed, the vertical arm of the latch member is projected into an active position above it, locking the treadle in its depressed position andthe' ironing members in 1ron1ng relation- 'In order to withdraw the latch member.

and of the padded roll requires the separation of. the ironing members immediately when they ceaseto function. Accordingly, the electromagnet 18 is connected to the same source of supply of electricity as the motor 15, thus providing for the deenergization of the mag netand the automatic release of the ironing members on the failure of power. Further, such connections provide for the energization of the electromagnet upon the closing of the motor circuit.

When ironing machines of this type are in use, it often becomes desirable to separate the ironing members in order to avoid injury to the operator or destruction of the articles being ironed. Accordingly, a switch 19, adapted for manual operation, is introduced into the circuit of the electromagnet so that, by its operation, the circuit may be broken at will to cause the deenergization of the magnet and the release of the treadle 13.

As shown in Fig. 1, two contact members, 20 and 21, are mounted on the shoe 12 and the ironing machine frame, respectively. These contact members are connected in series with the electromagnet 18 and serve to connect the latter across the source of supply of electric energy when the ironing members are moved into ironing relation with each other and to break the circuit when the ironing members are separated.

If, during the operation of an ironing machine, the motor is stalled by the application of too great a load, the ironin members cease to function and, in order to prevent the scorching of the articles being ironed, or perhaps, injury to the operator, it is desirable to provide for the automatic release of the latch and the immediate separation of the ironing members.

Accordingly, a modified form of the safety latch may be provided, as shown in Fig. 4 it being similar to the latch illustrated in Figs. 2 and 3 but having an electromagnet that is differentially wound. In this particular construction of the electromagnet .18, an auxiliary winding 29 is disposed inside of a main winding 28.

The modified form of latch may be utilized with diflerent types of motors and, in Fig. 5 is shown in conjunction with an induction motor. As will be observed, the main winding 28 of the electromagnet is connected in par allel with the stator winding 30, while the auxiliary winding is connected in series with it. The remainder of the connections may be the same as in Fig. 1, with a manually operated switch 19 inserted in the circuit of the main winding 28. In designing the windings 28 and 29 of the electromagnet, a suflicient number of turns is-provided in each to effect their neutralization when the rotor is at rest and a maximum current is flowing in the stator winding.

In the diagram of connections, a starting winding is indicated at 31 and an automatic switch at 32 which functions to cut out of the circuit the starting winding when the rotor 0 reaches a predetermined speed. As'any speed controlled automatic switch known in the art may be used, I do not deem it necessary to illustrate or describe it in detail, its effect being to cut the starting winding out of circuit 35 after the motor has been started and has reached a certain speed.

In the operation, the switch 22 is thrown to close the motor circuit and set the motor 15. in operation to rotate the roll 11. The switch 19 is then closed in order that the circuit of the electromagnet may be completed when the members 20 and 21 are moved into contact through the operation of the shoe 12.

The shoe 12 is moved into ironing relation with the roll 11 by the depression of the treadle 13. When the member 20 engages the member 21, the electromagnet 18 is energized and tends to rotate the latch member 16- clockwise, as viewed in Fig. 3, projecting the vertical arm against the side of the treadle. If the treadle is depressed to give the desired ironing pressure between the shoe and the roll, the vertical arm of the latch member is moved into position above the treadle, lock- 1 ing the ironing members in ironing relation. When the electromagnet operates to move the latch into its active or looking position, it tensions the spring 17., Consequently, when the electromagnet 18 is deenergized by .the breaking of its circuit, the snring 17 functions to withdraw the latch 16 from the treadle 13, thereby permitting the separation of the ironing members. Deenergization of the electromagnet results when the motor circuit is broken in any way, and the spring 17 operates to release the treadle 13.

By the manual operation of the switch'19, the magnet 18 may be deenergized at will, to provide for the release of the treadle 13 from 1 the latch. VVhenthe latch 16 has been withdrawn from engagement with the treadle 13, the circuit of the electromagnet 18 may be broken by the movement of the shoe 12 to its off position where it is separated from the roll 11. The circuit of the elect-roma net may be reestablished by the movement 0 the shoe 12 toward the roll 11, bringing the .contact members 20 and 21 into engagement.

It will be readily understood that the latch 16 may be stepped to permit the treadle to be locked in different positions to apply different pressures to the shoe 12. It is also pointed out that the contact member 20 is arc-shaped and serves to engage the member 21 throughout a considerable portion of the movement ofthe shoe 12.

Considering now the operation of the modified form of the safety latch shown in Fig. 4, when the main line switch is closed, the main winding 28 is energized. At the same time, the auxiliary winding 29 is energized by the current flowing through the stator winding and, since the magnet is differentially wound, the windings neutralize one another. When the starting winding 31 functions to set the rotor in operation, the current flowing in the stator winding 30 is decreased through the development of a counter electro-motive force in the motor.

As soon as the rotor reaches its normal speed, the current flowing in the winding 29 is reduced sufliciently to permit the main winding 28 to effect the operation of the latch 16.

Assuming that a load greater than the capacity of the machine is applied whereby the motor is brought to rest, no counter electromotive force is developed, and a large current, therefore, flows in the stator winding and in the auxiliary winding 29 of the electromagnet. In this manner, the magnetism induced in the core by the main winding 28 is neutralized, and the spring 17 is permitted to withdraw the latch 16 from its active position.

While the illustrated example constitutes a particular embodiment of my invention, I do not limit myself strictly to the exact details herein illustrated, since, manifestly, the same may be considerably varied without departing from the spirit of the invention as .vided with a movable ironing member comset forth in the appended claims.

I claim as my invention:

1. A safety latch for ironing machines embodying a frame, a rotatable ironing member supported in said frame,.an electric motor for effecting rotation of said ironing member, an ironing shoe, and a treadle connected to the ironing shoe to cause it to operatively engage the rotatable ironing member, said safety latch comprising a latch to lock the ironing shoe in operative engagement with the rotatable ironing member, an electromag- 'net for controlling the latch, cooperating contact members mounted respectively on said ironing shoe and on said frame, circuit connections between said contact members and said electromagnet to permit energization of the electromagnet when the ironing shoe is moved into operative engagement with the rotatable ironing member, and a spring connected to the latch to withdraw it when the electromagnet is deenergized.

2. The combination with an ironing machine embodying relatively movable ironing members and amotor for driving one of said ironing members, of means for locking said ironing members in ironing relation, electromagnetic means etfective when energized to operate said locking means to lock the ironing members in ironing relation, circuit connections between the motor and the electromagnetic means for energizing the electromagnetic means when the motor is energized, spring means for releasing said locking means, and means foracting on said electromagnetic means to prevent the release of said locking means except when the motor arma-.

ture speed is reduced below a predetermined value while the motor remains connected in circuit. I

3. A safety latch for ironing machines pro vided with a frame, a roll rotatably mounted on the frame and an ironing shoe movable into and out of ironing relation with said roll, comprising a latch member on the frame, an electromagnet to operate the latch member to lock the shoe in ironing relation with the roll, means operative to withdraw the latch member from its locked position when the electromagnet is deenergized and circuit closing means mounted on the frame and on the the circuit of said electromagnet when the shoe is moved into ironing relation with the roll.

4. A safety latch for'ironing machines pro- 2 HOMER E. NEWHOUSE. 

